Normothermia to Decrease Surgical Site Infection Risk: Silver Bullet or Fool's Gold? A Retrospective Cohort Study.

PURPOSE: Surgical site infection (SSI) is the leading cause of nosocomial infections among surgical patients in the United States. Currently, there is compelling evidence suggesting that temperature dysregulation in surgical patients may be a risk factor for the development of SSI. We examined the relationship between perioperative hypothermia (PH) and SSI in a population of surgical patients with diabetes mellitus (DM). METHODS: This retrospective cohort review was conducted on patients with a history of DM undergoing orthopaedic surgery at our institution between May 1, 2018, and April 1, 2022. Inclusion criteria were age older than 15 years, a history of DM or recent hemoglobin A1c concentration of ≥6.5%, and operation of at least 60 minutes under general anesthesia. Perioperative hypothermia was defined as an intraoperative temperature ≤ 35.5°C. Continuous variables were compared using the t-test and Wilcoxon rank-sum test. Categorical variables were compared using the chi-squared test. We constructed a multivariable logistic regression model to estimate SSI risk while controlling for demographic variables. RESULTS: A total of 236 patients were included in the final analysis. The overall incidence of SSI was 5.93%. 99 patients (42%) experienced PH. No difference was observed in the risk of SSI between the normothermic and hypothermic cohorts. Among the 99 patients who experienced PH, increasing HbA1c was associated with increasing risk of SSI (OR = 2.39, 95% CI = 1.12 to 5.32, P-value = 0.0222). The multivariable logistic regression model had good discriminatory ability (c-statistic 0.74, 95% CI: 0.61 to 0.89) and good predictive accuracy (sensitivity 64%, specificity 73%). DISCUSSION: PH is not an independent risk factor of SSI. However, in the presence of elevated HbA1c, PH may more than double the risk of SSI. Perioperative hypothermia may be an additive risk factor in the setting of poor glycemic control and potentially in the setting of other known risk factors.

The Effect of Brief Warming during Induction of General Anesthesia and Warmed Intravenous Fluid on Intraoperative Hypothermia in Patients Undergoing Urologic Surgery.

Background and Objectives: Transurethral urologic surgeries frequently lead to hypothermia due to bladder irrigation. Prewarming in the preoperative holding area can reduce the risk of hypothermia but disrupts surgical workflow, preventing it from being of practical use. This study explored whether early intraoperative warming during induction of anesthesia, known as peri-induction warming, using a forced-air warming device combined with warmed intravenous fluid could prevent intraoperative hypothermia. Materials and Methods: Fifty patients scheduled for transurethral resection of the bladder (TURB) or prostate (TURP) were enrolled and were randomly allocated to either the peri-induction warming or control group. The peri-induction warming group underwent whole-body warming during anesthesia induction using a forced-air warming device and was administered warmed intravenous fluid during surgery. In contrast, the control group was covered with a cotton blanket during anesthesia induction and received room-temperature intravenous fluid during surgery. Core temperature was measured upon entrance to the operating room (T0), immediately after induction of anesthesia (T1), and in 10 min intervals until the end of the operation (Tend). The incidence of intraoperative hypothermia, change in core temperature (T0-Tend), core temperature drop rate (T0-Tend/[duration of anesthesia]), postoperative shivering, and postoperative thermal comfort were assessed. Results: The incidence of intraoperative hypothermia did not differ significantly between the two groups. However, the peri-induction warming group exhibited significantly less change in core temperature (0.61 ± 0.3 °C vs. 0.93 ± 0.4 °C, p = 0.002) and a slower core temperature drop rate (0.009 ± 0.005 °C/min vs. 0.013 ± 0.004 °C/min, p = 0.013) than the control group. The peri-induction warming group also reported higher thermal comfort scores (p = 0.041) and less need for postoperative warming (p = 0.034) compared to the control group. Conclusions: Brief peri-induction warming combined with warmed intravenous fluid was insufficient to prevent intraoperative hypothermia in patients undergoing urologic surgery. However, it improved patient thermal comfort and mitigated the absolute amount and rate of temperature drop.

Effects of an early transfer from incubator to a warming crib in very low birthweight preterm infants.

PURPOSE: Very low birth weight infants are cared for postnatally in the incubator because of adverse consequences of hypothermia. Data on the optimal weight of transfer to a warming crib are rare. The aim of this study was to determine the course of temperature and body weight during a standardized transfer to a warming crib at a set weight. METHODS: Prospective intervention study in very low birthweight infants who were transferred from the incubator to a warming crib at a current weight between 1500 g and 1650 g. RESULTS: No infant had to be transferred back to an incubator. Length of hospital stay was equal compared to a historical cohort from the two years directly before the intervention. The intervention group showed an increase in the volume fed orally on the day after transfer to the warming crib, although this did not translate into an earlier discontinuation of gavage feedings. Compared to the historical group, infants in the intervention group could be transferred to an unheated crib at an earlier postmenstrual age and weight. CONCLUSIONS: Early transfer from the incubator to a warming crib between 1500 g and 1650 g is feasible and not associated with adverse short-term events or outcomes. TRIAL REGISTRATION: DRKS-IDDRKS00031832.

How three linked clinical observations led to an understanding of perioperative heat balance: A personal reflection on the scientific process.

Three linked clinical observations prompted our current understanding of perioperative heat balance. The first was the extraordinarily rapid decrease in core temperature after induction of general anesthesia which led to an understanding of redistribution hypothermia. The second was the linear reduction in core temperature during the subsequent 2-3 h which led to an understanding of anesthetic effects on metabolic heat production and factors that influence cutaneous heat loss. And the third was the observation that core temperature reaches a plateau at about 34.5 °C which led to the understanding that thermoregulatory vasoconstriction re-emerges when patients become sufficiently hypothermic, and that arteri-venous shunt constriction constrains metabolic heat to the core thermal compartment.

Implementation of a quality improvement initiative for standardising essential newborn care in a teaching public hospital in rural central India.

OBJECTIVE: Our aim was to refine the essential newborn care practices by employing the multidisciplinary peer team-led quality improvement (QI) projects. DESIGN: In 2017, concerning the same, the department focused on early initiation of breast feeding, prevention of hypothermia within an hour of life and rational usage of antibiotics among babies admitted to neonatal intensive care unit (NICU). Baseline data reported the rate of initiation of breast feeding, hypothermia and antibiotic exposure rate as 35%, 78% and 75%, respectively. Root causes were analysed and a series of Plan-Do-Study-Act cycles were conducted to test the changes. The process of change was studied through run charts (whereas control charts were used for study purpose). RESULT: After the implementation of the QI projects, the rate of initiation of breast feeding was found to be improved from 35% to 90%, the incidence of hypothermia got reduced from 78% to 10% and the antibiotic exposure rate declined from 75% to 20%. Along with the improvement in indicators related to essential newborn care, down the stream we found a decrease in the percentage of culture-positive sepsis rate in the NICU. CONCLUSION: Peer team-led QI initiatives in a resource-limited setting proved beneficial in improving essential newborn care practices.

Incidence and risk factors of neonatal hypothermia: A systematic review and meta-analysis.

AIM: Hypothermia poses a threat to the health and lives of newborns. Therefore, it is essential to identify the factors that influence neonatal hypothermia and provide targeted intervention suggestions for clinical practice to reduce its occurrence. METHODS: We conducted a literature search to identify factors influencing neonatal hypothermia and performed a meta-analysis to determine the prevalence of neonatal hypothermia and its associated factors. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort and case-control studies, while the Agency for Healthcare Research and Quality (AHRQ) was used to evaluate the quality of cross-sectional studies. RESULTS: Eighteen studies involving 44 532 newborns from 13 countries were included. The incidence of neonatal hypothermia was 52.5% (95% CI: 0.37, 0.68). Factors such as no skin-to-skin contact, prematurity, low birth weight, delayed breastfeeding, asphyxiation and resuscitation after birth, low APGAR score, not wearing a cap, and caesarean section were found to affect neonatal hypothermia. CONCLUSION: Multiple factors influence neonatal hypothermia, and clinicians can utilise these factors to develop targeted intervention measures to prevent and reduce the incidence of neonatal hypothermia.

Effect of a vapor barrier in combination with active external rewarming for cold-stressed patients in a prehospital setting: a randomized, crossover field study.

BACKGROUND: Use of a vapor barrier in the prehospital care of cold-stressed or hypothermic patients aims to reduce evaporative heat loss and accelerate rewarming. The application of a vapor barrier is recommended in various guidelines, along with both insulating and wind/waterproof layers and an active external rewarming device; however, evidence of its effect is limited. This study aimed to investigate the effect of using a vapor barrier as the inner layer in the recommended "burrito" model for wrapping hypothermic patients in the field. METHODS: In this, randomized, crossover field study, 16 healthy volunteers wearing wet clothing were subjected to a 30-minute cooling period in a snow chamber before being wrapped in a model including an active heating source either with (intervention) or without (control) a vapor barrier. The mean skin temperature, core temperature, and humidity in the model were measured, and the shivering intensity and thermal comfort were assessed using a subjective questionnaire. The mean skin temperature was the primary outcome, whereas humidity and thermal comfort were the secondary outcomes. Primary outcome data were analyzed using analysis of covariance (ANCOVA). RESULTS: We found a higher mean skin temperature in the intervention group than in the control group after approximately 25 min (p < 0.05), and this difference persisted for the rest of the 60-minute study period. The largest difference in mean skin temperature was 0.93 °C after 60 min. Humidity levels outside the vapor barrier were significantly higher in the control group than in the intervention group after 5 min. There were no significant differences in subjective comfort. However, there was a consistent trend toward increased comfort in the intervention group compared with the control group. CONCLUSIONS: The use of a vapor barrier as the innermost layer in combination with an active external heat source leads to higher mean skin rewarming rates in patients wearing wet clothing who are at risk of accidental hypothermia. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05779722.

Introduction of a Warming Bundle to Reduce Hypothermia in Neonatal Surgical Patients.

INTRODUCTION: Hypothermia in the neonatal surgical population has been linked with significant morbidity and mortality. Our goal was to decrease intra and postoperative hypothermia. INTERVENTION: In November 2021, a radiant warmer and hat were included along with standard warming methods prior to the start of General Surgery procedures to minimize episodes of hypothermia. PRIMARY OUTCOME: Core body temperature was measured pre, intra and post-operatively. METHODS: Data were prospectively collected from electronic medical records from July 2021 to March 2023. A retrospective analysis was performed. Hypothermia was defined as a temperature <36.5C. Control charts were created to analyze the effect of interventions. RESULTS: A total of 277 procedures were identified; 226 abdominal procedures, 31 thoracic, 14 skin/soft tissue and 6 anorectal. The median post-natal age was 36.1 weeks (IQR: 33.2-39.2), with a pre-surgical weight of 2.3 kg (IQR: 1.6-3.0) and operative duration of 181 min (IQR: 125-214). Hat and warmer data were unavailable for 59 procedures, both hat and warmer were used for 51 % procedures, hat alone for 29 %, warmer alone for 10 % and neither for 10 % of procedures. Over time there was a significant increase in hat utilization while warmer usage was unchanged. There was a significant increase in the mean lowest intra-operative temperature and decrease in proportion of hypothermic patients intra-operatively and post-operatively. CONCLUSIONS: The inclusion of a radiant warmer and hat decreased the proportion of hypothermic patients during and after surgery. Further studies are necessary to analyze the impact on surgical outcomes. LEVEL OF EVIDENCE: III.

Effect of wet clothing removal on skin temperature in subjects exposed to cold and wrapped in a vapor barrier: a human, randomized, crossover field study.

BACKGROUND: Prehospital care for cold-stressed and hypothermic patients focuses on effective insulation and rewarming. When encountering patients wearing wet clothing, rescuers can either remove the wet clothing before isolating the patient or isolate the patient using a vapor barrier. Wet clothing removal increases skin exposure but avoids the need to heat the wet clothing during rewarming. Leaving wet clothing on will avoid skin exposure but is likely to increase heat loss during rewarming. This study aimed to evaluate the effect of wet clothing removal compared to containing the moisture using a vapor barrier on skin temperature in a prehospital setting. METHODS: This randomized crossover experimental field study was conducted in a snow cave in Hemsedal, Norway. After an initial cooling phase of 30 min while wearing wet clothes, the participants were subjected to one of two rewarming scenarios: (1) wet clothing removal and wrapping in a vapor barrier, insulating blankets, and windproof outer shell (dry group) or (2) wrapping in a vapor barrier, insulating blankets, and windproof outer shell (wet group). The mean skin temperature was the primary outcome whereas subjective scores for both thermal comfort and degree of shivering were secondary outcomes. Primary outcome data were analyzed using the analysis of covariance (ANCOVA). RESULTS: After an initial decrease in temperature during the exposure phase, the dry group had a higher mean skin temperature compared to the wet group after only 2 min. The skin-rewarming rate was highest in the initial rewarming stages for both groups, but increased in the dry group as compared to the wet group in the first 10 min. Return to baseline temperature occurred significantly faster in the dry group (mean 12.5 min [dry] vs. 28.1 min [wet]). No intergroup differences in the subjective thermal comfort or shivering were observed. CONCLUSION: Removal of wet clothing in combination with a vapor barrier increases skin rewarming rate compared to encasing the wet clothing in a vapor barrier, in mild cold and environments without wind. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05996757, retrospectively registered 18/08/2023.

Comparison of the incidence of inadvertent perioperative hypothermia between general anesthesia and interscalene brachial plexus block in shoulder arthroscopy: A randomized prospective study.

INTRODUCTION: Inadvertent perioperative hypothermia (IPH), defined as core body temperature below 36°C, is associated with various complications. Shoulder arthroscopy is a risk factor of IPH. This study aimed to compare the incidence of IPH between general anesthesia (GA) and interscalene brachial plexus block (ISBPB) for shoulder arthroscopy. METHOD: Patients scheduled for shoulder arthroscopy were prospectively enrolled and randomly assigned to GA or ISBPB groups. The body temperature of the patients was measured from baseline to the end of anesthesia and in the post-anesthetic care unit to compare the incidence of IPH. RESULTS: Of the 114 patients initially identified, 80 were included in the study (GA = 40, ISBPB = 40). The incidence of IPH differed significantly between the groups, with GA at 52.5% and ISBPB at 30.0% (P = .04). Profound IPH (defined as < 35.0°C) occurred in 2 patients with GA. Upon arrival at the post-anesthesia care unit, the GA group exhibited a significantly lower mean body temperature (35.9 ±â€…0.6°C) than the ISBPB group (36.1 ±â€…0.2°C, P = .04). CONCLUSION: The incidence of IPH in the GA group was higher than that in the ISBPB group during shoulder arthroscopy, suggesting that ISBPB may be a preferable anesthetic technique for reducing risk of IPH in such procedures.

Polyethylene bags before cord clamping in very preterm infants: a randomised controlled trial.

OBJECTIVE: Hypothermia on admission to the neonatal intensive care unit (NICU) is associated with an increased risk of death in preterm infants. There are currently no evidence-based recommendations for thermal care before cord clamping (CC). We wished to determine whether placing very preterm infants in a polyethylene bag (PB) before CC, compared with after CC, results in more infants with a temperature in the normal range on NICU admission. DESIGN: Randomised controlled trial. SETTING: Tertiary maternity hospital. PATIENTS: Inborn infants<32 weeks' gestational age (GA). INTERVENTIONS: Infants were randomly assigned to have a PB placed before or after CC. MAIN OUTCOME: Rectal temperature within the normal range (36.5°C-37.5°C) on NICU admission. RESULTS: Between July 2020 and September 2022, 198/220 (90%) eligible infants were enrolled in this study; 99 (44 (44%) girls) were randomly assigned to BEFORE and 99 (53 (54%) girls) to AFTER. Median (IQR) GA 29 (27-31) vs 29 (27-31) weeks, mean (SD) birth weight 1206 (429) vs 1138 (419) g, respectively. The proportion of infants who had normal temperature on NICU admission did not differ between the groups (BEFORE 54/99 (55%) vs AFTER 55/98 (56%), p 0.824). The proportion of infants with a temperature outside of the normal range was similar between the groups; hypothermia (BEFORE 34/99 (34%) vs AFTER 33/98 (34%), hyperthermia (BEFORE 10/99 (10%) vs AFTER 10/98 (10%)). CONCLUSIONS: Placing a PB before CC did not increase the proportion of preterm infants with normal temperature on NICU admission. A large proportion of preterm infants had abnormal temperature. Further studies on thermoregulation before CC are needed. TRIAL REGISTRATION NUMBER: NCT04463511.

Effects of Heated Infiltration Solutions and Forced-Air Heating Blankets on Intraoperative Hypothermia During Liposuction: A Factorial Randomized Controlled Trial.

BACKGROUND: This study was conducted to compare the effects of heat preservation by two recommended methods, heated infiltration solutions and forced-air heating blankets, in patients undergoing liposuction under general anesthesia. METHODS: Forty patients were divided into four groups based on whether heated infiltration solutions or forced-air heating blankets were used. Group A received general anesthesia liposuction plastic surgery routine temperature care. Based on the care measures of group A, heated infiltration solutions were used in group B; forced-air heating blanket was used in group C; and heated infiltration solutions and forced-air heating blankets were both used in group D. The primary end point was intraoperative and perioperative temperature measured with an infrared tympanic membrane thermometer. Secondary end points included surgical outcomes, subjective experience, and adverse events. RESULTS: Compared with group A, the intraoperative body temperatures of groups B, C, and D were significantly higher, indicating that the two intervention methods were helpful on increasing the core body temperature. Pairwise comparisons of these three groups showed that there was no significant difference between group C and group D. However, using forced-air heating blankets had a marked effect compared with using heated infiltration solutions alone at three time points. The same trend could be seen in other surgical outcomes. CONCLUSIONS: Heated infiltration solutions and forced-air heating blankets could reduce the incidence of intraoperative hypothermia and improve patients' prognosis after liposuction under general anesthesia. Compared with the heated infiltration fluid, the forced-air heating blanket may have a better thermal insulation effect. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of 10 Minutes of Prewarming and Prewarmed Intravenous Fluid Administration on the Core Temperature of Patients Undergoing Transurethral Surgery under General Anesthesia.

Background: Patients undergoing transurethral urologic procedures using bladder irrigation are at increased risk of perioperative hypothermia. Thirty minutes of prewarming prevents perioperative hypothermia. However, its routine application is impractical. We evaluated the effect of 10 minutes of prewarming combined with the intraoperative administration of warmed intravenous fluid on patients' core temperature. Methods: Fifty patients undergoing transurethral bladder or prostate resection under general anesthesia were included in this study and were randomly allocated to either the control group or the prewarming group. Patients in the prewarming group were warmed for 10 minutes before anesthesia induction with a forced-air warming device and received warmed intravenous fluid during operations. The patients in control group did not receive preoperative forced-air warming and were administered room-temperature fluid. Participants' core body temperature was measured on arrival at the preoperative holding area (T0), on entering the operating room, immediately after anesthesia induction, and in 10-minute intervals from then on until the end of the operation (Tend), on entering PACU, and in 10-minute intervals during the postanesthesia care unit stay. The groups' incidence of intraoperative hypothermia, change in core temperature (T0 - Tend), and postoperative thermal comfort were compared. Results: The incidence of hypothermia was 64% and 29% in the control group and prewarming group, respectively (P = 0.015). Change in core temperature was 0.93 ± 0.3 °C and 0.55 ± 0.4 °C in the control group and prewarming group, respectively (P = 0.0001). Thermal comfort was better in the prewarming group (P = 0.004). Conclusions: Ten minutes of prewarming combined with warmed intravenous fluid significantly decreased the incidence of intraoperative hypothermia and resulted in better thermal comfort in patients undergoing transurethral urologic surgery under general anesthesia.

Thermoregulation for very preterm infants in the delivery room: a narrative review.

Abnormal temperature in preterm infants is associated with increased morbidity and mortality. Infants born prematurely are at risk of abnormal temperature immediately after birth in the delivery room (DR). The World Health Organization (WHO) recommends that the temperature of newly born infants is maintained between 36.5-37.5oC after birth. When caring for very preterm infants, the International Liaison Committee on Resuscitation (ILCOR) recommends using a combination of interventions to prevent heat loss. While hypothermia remains prevalent, efforts to prevent it have increased the incidence of hyperthermia, which may also be harmful. Delayed cord clamping (DCC) for preterm infants has been recommended by ILCOR since 2015. Little is known about the effect of timing of DCC on temperature, nor have there been specific recommendations for thermal care before DCC. This review article focuses on the current evidence and recommendations for thermal care in the DR, and considers thermoregulation in the context of emerging interventions and future research directions. IMPACT: Abnormal temperature is common amongst very preterm infants after birth, and is an independent risk factor for mortality. The current guidelines recommend a combination of interventions to prevent heat loss after birth. Despite this, abnormal temperature is still a problem, across all climates and economies. New and emerging delivery room practice (i.e., delayed cord clamping, mobile resuscitation trolleys, early skin to skin care) may have an effect on infant temperature. This article reviews the current evidence and recommendations, and considers future research directions.

A Warm Air Blanket is Superior to a Heated Mattress in Preventing Perioperative Hypothermia in Orthopedic Arthroplasties, a Time-Series Analyses.

BACKGROUND: Hypothermia is a common perioperative problem that can lead to severe complications. We evaluated whether a heated mattress (HM) is superior to a warm air blanket (WA) in preventing perioperative hypothermia in patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA). METHODS: A retrospective cohort study was performed in a teaching hospital and data were collected for all patients undergoing THA or TKA between January 1, 2015 and May 1, 2022. We used logistic and linear regressions to analyze hypothermia occurrence and important complications. Results were adjusted for confounders and time, and was present in all subgroups and after imputation of missing data. RESULTS: In total, 4,683 of 5,497 patients had information on type of heating. We found more perioperative hypothermia in patients treated with an HM compared to a WA for both THA (odds ratio-adjusted 1.42 [1.0 to 1.6] P = .06) and TKA (odds ratio-adjusted 2.10 [1.5 to 3.0] P < .01). There was no difference in postoperative infections between groups (all between 0.5% and 1.3%). Patients who had an HM significantly stayed longer in the postoperative ward (a mean difference of 4 [TKA] to 6 [THA] minutes, P < .01), but there was no difference in hospital stay. CONCLUSION: A WA is superior compared to an HM in preventing perioperative hypothermia, with no increased risk of complications. Patients who have an HM stayed longer at the postoperative ward, potentially because of higher hypothermia rates. Therefore, it is suggested to use a WA instead of an HM.

Correlation of opioid antinociception and hypothermia in dogs-An animal welfare refinement.

The purpose of this study was to assess antinociception and correlation of antinociception and hypothermic effects after intravenous opioids in dogs. Nine healthy male Beagles were enrolled in the study. They were acclimated to a thermal nociceptive device, then received three IV treatments (saline, butorphanol 0.4 mg/kg and methadone 0.5 mg/kg) in a randomized complete block design. Rectal temperature and thermal withdrawals were assessed prior to and 0.5-6 h after drug administration. One dog was excluded due to lack of withdrawal to thermal stimuli. Rectal temperatures were not significantly different between treatments at time 0, but significantly decreased from 0.5 to 5 h for both opioids compared to saline. Withdrawals were significantly decreased, compared to saline, from 0.5 to 4 h for butorphanol and 0.5-5 h for methadone. A significant (p = .0005) and moderate (R2 = .43) correlation between antinociception and hypothermia occurred. Based on these data, intravenous butorphanol (0.4 mg/kg) and methadone (0.5 mg/kg) provided 4 and 5 h of antinociception, respectively. Opioid hypothermia can serve as an easy, noninvasive and humane manner for preclinical assessment of opioid antinociception in dogs prior to evaluation in clinical trials. This is a major refinement in animal welfare for assessing novel opioids, opioid doses and dose intervals in dogs.

The Effect of Warmed Serum on Shivering and Recovery Period of Patients Under General and Spinal Anesthesia: A Randomized Clinical Trial.

PURPOSE: Postoperative hypothermia followed by shivering is a common phenomenon in patients undergoing surgery under anesthesia, and should be prevented and treated in postoperative patient care units. This study was conducted to investigate the effect of warmed serum injection on postoperative shivering and recovery period of patients operated under general and spinal anesthesia. DESIGN: In this clinical trial, patients to be operated on under general and spinal anesthesia were randomly assigned into two groups of test and control. In the test group, patients received warmed intravenous fluids and blood products. All patients were monitored to record vital signs, incidences of hypothermia and shivering, and recovery period. METHODS: The collected data were analyzed with repeated measures analysis of variance to detect significant differences between groups and significant changes within groups over time. FINDINGS: The incidence of nausea, vomiting, and shivering in the intervention and control groups was (4.7%, 42%), (2.8%, 16.8%), and (6.6%, 43%), respectively. Patients in the intervention group had higher body temperature than the control group (<0.001). Also, patients under spinal anesthesia had higher body temperature than patients under general anesthesia (<0.001). Blood pressure reduction was also significantly higher in the control group than in the intervention group. The patients who received warm intravenous serum, and especially those who had received spinal anesthesia spent less time in the recovery room (<0.001). CONCLUSIONS: The use of warmed intravenous serum increased the patients' core temperature, reduced their postoperative shivering, and shortened their recovery period. Considering the potential risks associated with hypothermia, using such methods for hypothermia prevention can be highly effective in preventing shivering and prolongation of the recovery period and other potential complications. Anesthesia specialists and technicians are therefore encouraged to use this method as a preventive measure.

Preventing hypothermia in pediatric neurosurgery in Africa-A randomized controlled non-inferiority trial of insulation versus active warming.

PURPOSE: The objective of this study was to compare the efficacy of a low-cost heat-preserving method in preventing intraoperative hypothermia with that of forced-air warming in a resource-limited setting. METHODS: In this randomized controlled non-inferiority trial, we recruited children younger than 12 years scheduled for cranial neurosurgery in a large East-African hospital. Patients were block-randomized by age to intraoperative warming measures using Hibler's method (intervention) or warm air (comparator). Hibler's group patients were circumferentially wrapped in transparent plastic sheeting (providing a vapor-trap) over a layer of cotton blankets, then laid on an insulating foam mattress. Warm air group patients were treated with forced-air convection via an underlying Snuggle Warm™ Pediatric Full Body mattress. Allocated warming measures were initiated in the operating theatre and discontinued upon anesthesia emergence. Perioperative temperatures were measured using noninvasive forehead probes (SpotOn™). The primary outcome was incidence of hypothermia (core temperature < 36.0° for longer than 5 min). Our null hypothesis was that Hibler's method is inferior in efficacy to the warm air method by a margin exceeding 20%. Among secondary outcomes were duration of hypothermia as proportion of surgical duration, incidence of postoperative shivering and rescue measure requirements. RESULTS: We analyzed data for 77 participants (Hibler's = 38; warm air = 39). There was no significant difference between the Hibler's and warm air arms of the study in the primary outcome of incidence of hypothermia (59.0% vs. 60.5% respectively; OR 1.07; 95% CI 0.43-2.65; p = .890). However, the risk difference (1.55%; 95% CI -0.20 to -0.24) exceeded the 0.2 margin and non-inferiority could not be declared. There was considerable need for rescue measures in both groups (71.1 0% vs. 69.2%; OR 1.09; 95% CI 0.41-2.90; p = .861). There was no statistically significant difference between groups for any prespecified secondary outcome. CONCLUSION: Although perioperative core temperatures were not significantly different, we could not declare an inexpensive heat-preserving method non-inferior to warm air convection in preventing intraoperative hypothermia in children undergoing anesthesia for cranial neurosurgery in a resource-limited setting. The extensive need for rescue measures may have masked important differences. TRIAL REGISTRATION: US National Institutes of Health Clinicaltrials.gov database (ID no. NCT02975817).

Effect of preoperative warming on intraoperative hypothermia and postoperative functional recovery in total hip arthroplasty: a randomized clinical trial.

BACKGROUND: Intraoperative hypothermia is associated with increased morbidity and impaired postoperative recovery. Direct anterior-approached total hip arthroplasty (ATHA) may lead to significant thermal loss. We aimed to assess whether preoperative warming had an impact on intraoperative hypothermia and postoperative functional recovery after ATHA. METHODS: In this prospective randomized controlled clinical trial 40 patients scheduled for ATHA were randomly divided into two groups of 20 patients each. Group W received, prior to the induction of general anesthesia, a 30 minutes 43 °C forced-air preoperative warming. Group C did not receive any preoperative warming. A blinded observer noted the core body temperature at the time of induction and at fixed time points, i.e. every five minutes during the first hour of surgery. The evolution of postoperative patient perceived thermal comfort (TC) and functional recovery (QoR-15) was assessed 24, 48 and 72 hours after surgery. Length of stay in the post-anesthesia care unit (PACU) was noted. RESULTS: The temperature drop was significantly faster and of higher amplitude in group C than in group W, during first hour of surgery (P<0.001). Evolution of QoR-15 and TC was significantly better in group W than in group C (P<0.001 for QoR-15 and P<0.001 for thermal comfort), with shorter length of stay (median [IQR]) in the PACU (minutes; 73 [61-79] for group C and 98 [83-129] for group W, P<0.001). CONCLUSIONS: In ATHA, pre-warming delays and reduces intraoperative heat loss, impacting patient comfort and postoperative functional recovery.